The present invention generally relates to self-contained portable energy storage devices, such as electrochemical cells. More particularly, the present invention relates to primary alkaline batteries and battery packs and also to alternative forms of energy storage devices.
Many of today""s electronic devices, such as toys, radios, flashlights, etc., are powered using self-contained portable energy storage devices. Due to their high-energy storage density, batteries and battery packs have dominated the self-contained energy storage device market. Such batteries and battery packs are either primary or secondary (e.g., rechargeable).
In the primary battery market, there is an ever-present demand for longer lasting batteries. In the secondary battery market, there exists demands for increased cycle life, decreased charging times, and the ability to design secondary battery packs that are either smaller than current designs or allow for a more flexible shaping of the battery pack for use in connection with video cameras, cellular telephones, personal electronic organizers, and laptop computers that are increasingly being made smaller.
Accordingly, it is an aspect of the present invention to provide a self-contained portable energy storage device that meets the above-identified market demands. More particularly, it is an aspect of the present invention to provide a rechargeable energy storage device having a virtually unlimited cycle life. It is another aspect of the present invention to provide a rechargeable self-contained energy storage device that may be recharged to its full potential in a fraction of the time taken to recharge conventional secondary battery packs. An additional aspect of the present invention is to provide a rechargeable self-contained energy storage device that may be configured into a wider variety of shapes and sizes than can be achieved with conventional rechargeable battery packs.
To achieve these and other aspects and advantages, the self-contained portable energy storage device of the present invention comprises a housing having first and second external contact terminals, a high-energy storage capacitor disposed in the housing and coupled between first and second internal terminals, and a voltage converter disposed in the housing and coupled to the first and second internal terminals. The voltage converter is coupled to the first and second external contact terminals to convert the voltage appearing at the first and second internal terminals to a substantially constant voltage that the voltage converter applies to the first and second external contact terminals.
Another aspect of the present invention is to provide a primary battery having increased service life. To achieve this and other aspects and advantages, the primary battery of the present invention comprises a housing having first and second external contact terminals, at least one primary electrochemical cell disposed in the housing and electrically coupled between a first terminal and a second terminal, and a voltage converter disposed within the housing. The voltage converter is coupled to the second terminal and is coupled between the first terminal and the first external contact terminal to convert the voltage applied to the first and second terminals by the primary electrochemical cell to a substantially constant voltage that the voltage converter applies between the first and second external contact terminals.